Topic
Colossal magnetoresistance
About: Colossal magnetoresistance is a research topic. Over the lifetime, 3658 publications have been published within this topic receiving 130104 citations.
Papers published on a yearly basis
Papers
More filters
TL;DR: It is shown that the superconductivity is mediated by charge fluctuations and the Cooper pairs have d(xy) symmetry, in contrast to the kappa-(BEDT-TTF)(2)X family, for which theoretical calculations givesuperconductivity mediated by spin fluctuations and with d(x(2)-y(2)) symmetry.
Abstract: The issue of the interplay of superconductivity, mag-netism, and charge ordering is relevant to a wide rangeof strongly correlated electron materials. Examples in-clude the copper-oxide (high-temperature) superconduc-tors [1], colossal magnetoresistance materials [2], heavyfermion compounds [3], vanadium oxides [4], and organicmolecular crystals [5–7]. In particular, for the cuprate su-perconductors there is controversy about the relative im-portance of charge fluctuations (associated with dynamical“stripes”) and antiferromagnetic spin fluctuations (associ-ated with the Mott insulator which occurs when there is anaverage of one electron or hole for every lattice site). Forsome heavy fermion compounds recent experiments sup-port the idea that the superconductivity is mediated by spinfluctuations [3].The family k- BEDT-TTF
184 citations
TL;DR: In this paper, the resistivity and magnetoresistance of a magnetite single crystal and Fe3 O4 films of various thicknesses were measured in the temperature range 70 K
Abstract: The resistivity and magnetoresistance of a magnetite single crystal and Fe3 O4 films of various thicknesses were measured in the temperature range 70 K
183 citations
TL;DR: These results may provide a general method for controlling the magnetotransport properties of manganite-based composite films by appropriate choice of the second phase of the MgO second phase.
Abstract: 'Colossal magnetoresistance' in perovskite manganites such as La0.7Ca0.3MnO3 (LCMO), is caused by the interplay of ferro-paramagnetic, metal-insulator and structural phase transitions. Moreover, different electronic phases can coexist on a very fine scale resulting in percolative electron transport. Here we report on (LCMO)1-x:(MgO)x (0 < x < or = 0.8) epitaxial nano-composite films in which the structure and magnetotransport properties of the manganite nanoclusters can be tuned by the tensile stress originating from the MgO second phase. With increasing x, the lattice of LCMO was found to expand, yielding a bulk tensile strain. The largest colossal magnetoresistance of 10(5)% was observed at the percolation threshold in the conductivity at xc 0.3, which is coupled to a structural phase transition from orthorhombic (0 < x < or 0.1) to rhombohedral R3c structure (0.33 < or = x < or = 0.8). An increase of the Curie temperature for the Rc phase was observed. These results may provide a general method for controlling the magnetotransport properties of manganite-based composite films by appropriate choice of the second phase.
183 citations
TL;DR: This work considers the cooperative nature of the Mn-oxide lattice distortions and induces power-law correlations in the quenched disorder used in toy models with phase competition, qualitatively modifying previous scenarios and solving the puzzle.
Abstract: Previous theoretical investigations of colossal magnetoresistance (CMR) materials explain this effect using a "clustered" state with preformed ferromagnetic islands that rapidly align their moments with increasing external magnetic fields. While qualitatively successful, explicit calculations indicate drastically different typical resistivity values in two- and three-dimensional lattices, contrary to experimental observations. This conceptual bottleneck in the phase-separated CMR scenario is resolved here considering the cooperative nature of the Mn-oxide lattice distortions. This effectively induces power-law correlations in the quenched disorder used in toy models with phase competition. When these effects are incorporated, resistor-network calculations reveal very similar results in two and three dimensions, qualitatively modifying previous scenarios and solving the puzzle.
182 citations
TL;DR: In this paper, the angular dependence of the magnetoresistance in a WTe2 single crystal was studied and the significant anisotropic magnetotransport behavior in different magnetic field directions and violation of the Kohler's rule was observed.
Abstract: Recently, the WTe2 semimetal, as a typical layered transition-metal dichalcogenide, attracted much attention due to an extremely large, non-saturating parabolic magnetoresistance in the perpendicular field. Here, we report a systematic study of the angular dependence of the magnetoresistance in a WTe2 single crystal. The significant anisotropic magnetotransport behavior in different magnetic field directions and violation of the Kohler's rule are observed. Unexpectedly, when the applied field and excitation current are both parallel to the tungsten chains of WTe2, an exotic large longitudinal linear magnetoresistance as high as 1200% at 15T and 2K is identified. These results imply that the WTe2 semimetal, due to its balanced hole and electron populations, seems to be the first material for which a large longitudinal linear magnetoresistance appears when the external magnetic field is parallel to the applied current. Finally, our work may stimulate studies of double-carrier correlated materials and the corresponding quantum physics.
179 citations